Natural Family Planning
Couple to Couple League
The Couple to Couple League (CCL) is an international, Catholic, non-profit organization dedicated to promoting and teaching fertility awareness (natural family planning) to married and engaged couples.
www.ccli.org/
http://nfpandmore.org/
Natural Family Planning information and resources
nfpandmore.org/
Natural Family Planning
The Wikipedia page for Natural Family Planning
en.wikipedia.org/wiki/Natural_family_planning